It is generally known that wed-shaped semimanufactured products, such as of paper, of synthetic materials, of woven fabrics or also of precious metals are to be freed of dust, dirt and lint prior to subsequent treatment thereof, for example, in order to prevent misprinting in the printing factory, fouling of processing baths in the finishing shops and so forth.
Prior art dust-collecting devices, in particular with air jets, are not, however, in a position to meet the increasing demands on the degree of dust collecting. If, for example, a web of textile fabric is fed at 60 m/mm over a suction slit having a width of 20 mm, then the effective time of the air current amounts to approximately 0.02 sec. This is seldom suffucient for an effective cleaning and is absolutely useless for flocked webs of material.
It is, therefore, a primary object of this invention to provide a device of the aforementioned kind which, despite the high feed velocity of the web, ensures a long effective time of the air current and thus an optimum cleaning.